Biobutanol: A renewable fuel that is similar to ethanol and can be made from corn and other crops or biomass. Biobutanol contains more energy than ethanol and has some beneficial characteristics that make it compatible with existing fuel distribution networks. However, it is still in the early stages of development and research is ongoing. Should its production become cost-effective, existing ethanol plants could be retrofitted to produce biobutanol.

Biodiesel: A renewable fuel in which soy or canola oil is refined through a special process and blended with standard diesel fuel. Biodiesel does not contain ethanol, but research is underway to develop diesel blends with ethanol (See “Ethanol-Diesel” below).

Biomass: Plant matter such as trees, grasses, agricultural crops or other biological material.

Carbon monoxide: A deadly gas produced from the tailpipe when cars burn gasoline. Ethanol in unleaded gasoline helps reduce carbon monoxide emissions by as much as 30 percent.

Clean Air Act: In 1990, Congress passed amendments to the Clean Air Act, which set minimum standards for air quality in America 's cities. Cities with excessive amounts of carbon monoxide and ozone must develop programs to battle air pollution.

Clean fuels: Fuels such as E-10 Unleaded that burn cleaner and produce fewer harmful emissions compared to ordinary gasoline.

Co-Products: Other products made by ethanol plants as a result of ethanol production. Depending on the type of ethanol facility, co-products can include livestock feed, corn sweeteners, corn oil, carbon dioxide and other value-added products.

Distillers grains: A co-product of dry mill ethanol production that is fed to livestock. May also be referred to as DDGS (dried distillers grains with solubles, but can be fed "wet" (undried) to cattle.)

Dry mill: An ethanol production process in which the entire corn kernel is first ground into flour before processing. In addition to ethanol, dry mills also produce distillers grains that are fed to livestock and carbon dioxide that is used in food processing and bottling. Most new ethanol plants are dry mill facilities.

E-10 Unleaded: Ordinary unleaded gasoline enhanced with ethanol, which is blended at a rate of 10 percent (10 percent ethanol and 90 percent regular unleaded). E-10 Unleaded is approved for use by every major automaker in the world.

Back to top

E85: A blend of 85 percent ethanol and 15 percent ordinary unleaded gasoline. This fuel mixture is used in Flexible Fuel Vehicles (see below).

Ethanol-Diesel: A blend of ethanol and diesel fuel plus other additives designed to reduce air pollution from heavy equipment, city buses and other vehicles that operate on diesel engines.

ETBE: Ethyl tertiary butyl ether—a fuel derived from ethanol that offers advantages in terms of lower volatility and blending.

Ethanol: A clean-burning, high octane, renewable fuel additive made from grain or other biomass sources.

Flexible Fuel Vehicle (FFV): A car or truck that can run on any blend of unleaded gasoline with up to 85 percent ethanol (E85). If you own an FFV, you do not have to fill up with E85 every time. A computer in the fuel system automatically compensates for the varying levels of ethanol in the fuel to assure optimum performance at all times.

Back to top

Methanol: A fuel additive made from fossil fuels such as coal, petroleum and natural gas. Many car warranties do not cover the use of methanol-based fuels, while all approve the use of ethanol blends.

MTBE: Methyl tertiary butyl ether—a fuel additive derived from methanol. MTBE has been discovered in groundwater supplies. MTBE has been phased out across the United States.

Net energy balance: The difference between the energy produced and the energy it takes to produce it. Research has shown that ethanol has a net energy balance of 1.67 to 1, meaning that for every 100 BTUs of energy used to make ethanol, 167 BTUs of ethanol are produced.

Non-attainment cities: Those areas of the country that do not meet minimum standards for air quality. These cities have excessive rates of carbon monoxide and/or ozone in their air.

Octane rating: The octane rating of a fuel is indicated on the pump—using numbers such as 87, 90, 91, etc. The higher the number, the greater the octane rating of the gasoline. The octane rating represents the "antiknock" properties of the fuel. The higher the number, the slower the fuel burns—and the less likely your engine will knock. Ethanol typically adds two to three octane numbers when blended with ordinary gasoline—making it a cost-effective octane-enhancer.

Back to top

Oxygenated fuels: Ethanol is an oxygenate, meaning that it adds oxygen to the fuel mixture. More oxygen helps the fuel burn more completely—reducing the amount of harmful emissions from the tailpipe. A fuel such as ethanol-blended gasoline that contains a high oxygen content is called "oxygenated."

Ozone: Much like cholesterol, there is "good" ozone and "bad" ozone. The good ozone (atmospheric) lies in the upper reaches of the atmosphere, helping protect us from ultraviolet radiation from the sun. However, when ground level ozone (tropospheric) is in the air we breathe, it's not healthy. What we commonly call "smog" is really ozone and other pollutants built-up in the air. The use of ethanol-blended gasoline has been shown to help reduce tropospheric ozone levels.

Particulate Matter (PM): “Pieces” of air pollution that have been found to penetrate deeply into human lungs. Ethanol helps reduce PM emissions by more than 25 percent.

Reformulated gasoline: Reformulated gasoline (RFG) is a cleaner-burning blend of gasoline that reduces motor fuel emissions. While RFG contains the same ingredients found in conventional gasoline, it reduces some of the more harmful, toxic compounds and adds more combustible, cleaner-burning compounds. As a result, RFG can be efficiently, safely and cost-effectively used in today's cars—using the same refueling methods and with no appreciable difference on vehicle performance. Since its introduction in January 1995, RFG has eliminated approximately 300 million tons of pollution from the nation's atmosphere. (U.S. Environmental Protection Agency)

Back to top

Renewable Fuels Standard (RFS): Part of federal energy legislation that sets a minimum number of gallons of renewable fuels to be used in the nation’s transportation fuel supply each year. The RFS includes fuels such as ethanol and biodiesel.

Vapor lock: An engine performance problem due to high vapor pressure in fuel. While ethanol increases the vapor pressure of fuel, state and federal standards continue to lower vapor pressure levels—virtually eliminating vapor lock problems. Additionally, all major auto manufacturers now use in-tank fuel pumps, which are not subject to the vapor lock problems seen in older in-line fuel pumps.

VEETC: Stands for Volumetric Ethanol Excise Tax Credit, 2004 federal legislation that strengthened the nation’s commitment to renewable fuels by extending tax incentives for ethanol and biodiesel, improving flexibility for petroleum companies to blend ethanol, and ensuring that Highway Trust Fund revenues are not adversely affected by increased ethanol use.

VOC: Volatile organic compounds—air pollutants found in engine exhaust. Ethanol helps reduce VOC emissions by 12 percent.

Wet mill An ethanol production facility in which the corn is first soaked or “steeped” in water before processing. In addition to ethanol, wet mills have the ability to produce co-products such as industrial starch, food starch, high fructose corn syrup, gluten feed and corn oils.

Back to top